Urinary cadmium and osteoporosis in U.S. Women >or= 50 years of age: NHANES 1988-1994 and 1999-2004.
BACKGROUND
Urinary cadmium (U-Cd) has been associated with decreased peripheral bone mineral density (BMD) and osteoporosis. This association, however, has not been confirmed using femoral BMD, the international standard for diagnosing osteoporosis, at levels < 1.0 microg Cd/g creatinine.


OBJECTIVE
Our goal was to investigate the statistical association between U-Cd, at levels <or= 1 microg/g creatinine, and osteoporosis, as indicated by hip BMD and self-report in a population-based sample of U.S. women >or= 50 years of age.


METHODS
We drew data from the National Health and Nutrition Examination Surveys for 1988-1994 (n = 3,207) and 1999-2004 (n = 1,051). Osteoporosis was indicated by hip BMD cutoffs based on the international standard and self-report of physician diagnosis. We analyzed U-Cd levels for association with osteoporosis using multiple logistic regression.


RESULTS
Women >or= 50 years of age with U-Cd levels between 0.50 and 1.00 microg/g creatinine were at 43% greater risk for hip-BMD-defined osteoporosis, relative to those with levels <or= 0.50 microg/g (odds ratio = 1.43; 95% confidence interval, 1.02-2.00; p = 0.04). We observed similar effect estimates using self-report of physician-diagnosed osteoporosis. Smokers did not show a statistically increased risk.


CONCLUSIONS
Results suggest that U.S. women are at risk for osteoporosis at U-Cd levels below the U.S. Occupational Safety and Health Administration's 3-microg/g safety standard. Given null findings among smokers, dietary Cd, rather than tobacco, is the likely source of Cd-related osteoporosis risk for the U.S. female population >or= 50 years of age.
Gallagher
Carolyn M
CM
Graduate Program in Public Health, Stony Brook University Medical Center, Stony Brook, New York 11790, USA. 2crgallagher@optonline.net
Kovach
John S
JS
Meliker
Jaymie R
JR
D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002104:Cadmium / Q000652:urine*; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D008875:Middle Aged; D009749:Nutrition Surveys; D010024:Osteoporosis / Q000453:epidemiology* / Q000652:urine; D012044:Regression Analysis; D014481:United States / Q000453:epidemiology
D002104:Cadmium; D003404:Creatinine